Motion Assistance Apparatus Ankle Joint Dynamics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rapidly aging societies face challenges with joint problems, leading to increased inconvenience and pain, necessitating effective walking assistance solutions for the elderly and patients with joint issues.
Innovation Solution
A motion assistance apparatus featuring a proximal support, drive links, a support joint, and a torque providing device that enables translational and rotational motions, with elastic bodies and sub-actuators to assist ankle movements, including dorsi-flexion and plantar-flexion, while preventing unintended inversion or eversion motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a motion assistance apparatus is designed to assist ankle movements, then walking effort is reduced, but the device complexity increases due to multiple drive links and torque providing mechanisms
Solution Approach 1:
The motion assistance apparatus employs dynamic mechanisms including a first drive link performing translational motion and a second drive link performing both translational and rotational motions. The support body rotates about a remote center of motion to dynamically assist ankle movements during walking, reducing walking effort while managing device complexity through functional dynamics
Solution Approach 2:
The apparatus is segmented into multiple functional components: proximal support, distal support, support body, first drive link, second drive link, coupling link, and connecting link. Each segment performs a specific function in the kinematic chain, allowing the complex assistance task to be divided into manageable mechanical operations that reduce overall system complexity
2Stability of the object's composition
If elastic bodies are used to prevent unintended inversion or eversion motions, then joint stability is improved, but the device complexity increases due to additional torque providing mechanisms
Solution Approach 1:
Elastic bodies are integrated into the second drive link to provide torque that automatically prevents unintended inversion or eversion motions of the ankle joint. The elastic bodies self-regulate the joint position through their elastic properties, maintaining joint stability without requiring additional active control mechanisms or sensors, thus managing device complexity
Solution Approach 2:
The elastic bodies act as intermediary elements between the second drive link and the ankle joint, providing a passive torque mechanism that mediates unwanted joint movements. This intermediary approach stabilizes the joint through mechanical elasticity rather than requiring complex active control systems
3Adaptability or versatility
If the first drive link moves at a faster velocity than the second drive link, then the support body can perform both translational and rotational motions, but the manufacturing precision requirements increase
Solution Approach 1:
The first drive link is designed to move at a faster velocity than the second drive link, enabling the support body to simultaneously perform translational and rotational motions about a remote center of motion. This dynamic velocity differential provides adaptability for natural ankle movement patterns while the mechanism design accommodates the resulting precision requirements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus reduces the effort required for walking by assisting joint motions, preventing falls, and providing support tailored to individual elastic coefficients for effective motion assistance.
Implementation Method 1
an elastic body configured to deform in response to rotation of the support joint about the second drive link
Data Source
AI summary
A motion assistance apparatus includes a proximal support configured to support a proximal part of a user, a first drive link and a second drive link configured to perform translational motions with respect to the proximal support at different velocities, a support joint rotatably connected to the second drive link, a support body connecting the first drive link and the support joint, the support body configured to simultaneously perform a translational motion and a rotational motion with respect to the proximal support, a distal support connected to the support body, the distal support configured to support a distal part of the user, and a torque providing device configured to provide a torque to rotate the support joint.